Railroad hopper car with bottom discharge doors having angled seals and actuating assemblies

ABSTRACT

Methods and systems are provided for a railroad hopper car bottom discharge door having two door plates, where at least one is rotatable between open and closed positions for the bottom discharge door. A seal member is fixedly connected to a distal end of each door plate, respectively, and each seal member has a seal lip protruding from the corresponding door plate. One seal lip comprises a first obtuse angle on a lower surface of the seal lip, while the other seal lip comprises a second angle smaller than the first obtuse angle on an upper surface of the seal lip. When the bottom discharge door is closed, the two angles on the two seal lips interlock to form a seal. Methods and systems for a door-actuating assembly that utilizes a pick-up shoe and a rechargeable battery to minimize the occurrence of rail sparks inside dump sites are also provided.

NOTICE OF COPYRIGHTS AND TRADE DRESS

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. This patent document may showand/or describe matter which is or may become trade dress of the owner.The copyright and trade dress owner has no objection to the facsimilereproduction by anyone of the patent disclosure as it appears in theU.S. Patent and Trademark Office files or records, but otherwisereserves all copyright and trade dress rights whatsoever.

FIELD OF THE INVENTION

Embodiments of the present invention are in the field of manufacturingtechnology of railroad freight cars, and in particular, to bottomdischarge door devices and actuating systems, and a hopper car havingthe same.

BACKGROUND OF THE INVENTION

The statements in the background of the invention are provided to assistwith understanding the invention and its applications and uses, and maynot constitute prior art.

A hopper car is a type of railroad freight car used to haul bulkcommodities such as coals, fertilizers, grains, and iron ores. A hoppercar may be covered or open on top, and discharges its load through doorslocated on the underside of the car body. Automatic unloading ofmaterials from a hopper car may be facilitated at designated dumpingsites, where an electric current collector shoe or pickup shoe may slideover an energized trackside conductor rail to operate anelectro-pneumatic control valve to open and close discharge doors.

One issue in hopper car design is in the sealing mechanism of bottomdischarge doors. As bulk commodities are generally pelletized, granular,or particulate, poor sealing performance of a discharge door device maycause material leakage onto rail tracks, resulting in economic loss,adverse effects to drainage of the track bed, and possible environmentalpollutions. Such effects are especially severe when materials aretransported over long distances under various weather conditions.

Another issue in hopper car design is safety considerations foroperations in confined dumping spaces such as buildings, unloadingsheds, and grain elevators. Conventional bottom discharge hopper carsuse pick-up shoes that slide across an electrified conductor rail totransmit electrical signals to the control valve, for automaticallyopening and closing one or more bottom discharge doors. When a tight,direct contact between a pick-up shoe and the conductor rail is lost,for example due to dirt or leaves on the rail, an electric arc may jumpacross the gap, creating sparks that can in turn ignite a fire orexplosion within a confined space if dusts or similar combustibleparticulate materials are present in high-enough concentrations. As aresult, unloading of hopper cars often occur in vented open spacesoutside of processing and storage facilities.

Therefore, in view of the aforementioned difficulties, it would be anadvancement in the state of the art to provide railroad hopper cardesigns with durable and long-lasting discharge doors and/or pick-upshoe arrangements and actuating assemblies that mitigate or preventhazardous dust explosions.

It is against this background that the present invention was developed.

BRIEF SUMMARY OF THE INVENTION

The inventors of the present invention have created methods and systemsfor a bottom discharge door, comprising a first door plate, a seconddoor plate, a first seal member, and a second seal member. The firstdoor plate comprises a first hinged end and a first distal end oppositeto the first hinged end; the second door plate comprises a second hingedend and a second distal end opposite to the second hinged end. The firstseal member comprises a first attachment portion and a first seal lip;the second seal member comprises a second attachment portion and asecond seal lip. The first seal member is fixedly connected to the firstdistal end at the first attachment portion, the first seal lip protrudesfrom the first distal end, and the first seal lip comprises a firstobtuse angle on a lower surface of the first seal lip. The second sealmember is fixedly connected to the second distal end at the attachmentportion, the second seal lip protrudes from the second distal end, andthe second seal lip comprises a second angle smaller than the firstangle, on an upper surface of the second seal lip. At least one of thefirst and second door plates is rotatable around its hinged end, betweena closed position and an open position for the bottom discharge door,and when the bottom discharge door is in the closed position, the firstobtuse angle interlocks with the second angle to form a seal.

In some embodiments of the present invention, the first obtuse angle ismeasured between 93 degrees inclusive and 95 degrees inclusive. In someembodiments, the second angle is a right angle.

In some embodiments, the first attachment portion is a flat plate, thefirst attachment portion and the first seal lip form a third obtuseangle on a lower surface of the first seal member, and the third angleis measured between 145 degrees inclusive and 150 degrees inclusive. Insome embodiments, the second attachment portion is a flat plate, and thesecond attachment portion and the second seal lip form a right angle ona lower surface of the second seal member.

In some embodiments, the first seal member is fixedly connected thefirst distal end at the first attachment portion through welding,bolting, or clamping, and the second seal member is fixedly connected tothe second distal end at the second attachment portion through welding,bolting, or clamping.

In some embodiments, each of the first and second seal lips compriseselastically deflects when the bottom discharge door is in the closedposition.

In some embodiments, each arm of each of the first obtuse angle and thesecond angle measures at least 2 inches in length.

In another aspect, the present invention is a railroad hopper car withbottom discharge doors having angled seals, comprising a body, aplurality of hoppers along an underside of the body, and a plurality ofbottom discharge doors as disclosed above, situated on the underside ofbody for opening and closing the plurality of hoppers.

In some embodiments, the railroad hopper car further comprises adoor-actuating assembly for actuating the bottom discharge doors. Thedoor-actuating assembly comprises a pick-up shoe, a battery, ahermetically seal switch, and an electro-pneumatic valve electricallyconnected in series. The battery is rechargeable via the pick-up shoewhen the pick-up shoe is biased into an active position having physicalcontact with a wayside conductor rail. The hermitically sealed switch iselectrically connected to the battery at a first terminal, andelectrically connected to an electro-pneumatic valve at a secondterminal. The electro-pneumatic valve actuates the bottom discharge doordevice between the open position and the closed position, after thebattery is charged beyond a pre-determined state of charge, and afterthe pick-up shoe is biased into an inactive position not having physicalcontact with the wayside conductor rail.

In yet another aspect, the present invention is a method for actuating arailroad hopper car bottom discharge door, comprising the steps ofturning off a hermetically sealed switch electrically connected betweena rechargeable battery and an electro-pneumatic valve; biasing a pick-upshoe into an active position having physical contact with a waysideconductor rail to charge the rechargeable battery, wherein therechargeable battery is electrically connected to the pick-up shoe, andwherein the rechargeable battery is electrically insulated from theelectro-pneumatic valve, determining whether the battery is chargedbeyond a pre-determined state of charge; and in response to determiningthat the battery is charged beyond a pre-determined state of charge,biasing the pick-up shoe into an inactive position not having physicalcontact with the wayside conductor rail, and turning on the hermeticallysealed switch to activate the electro-pneumatic valve, to actuate thebottom discharge door device between an open position and a closedposition.

In some embodiments, the battery is a capacitor. In some embodiments,the electro-pneumatic valve operates between 24 VDC and −24 VDC.

In some embodiments, the pick-up shoe is spring-biased. In someembodiments, the pick-up shoe further comprises a base plate adapted tobe attached to the railroad hopper car, an electrical contact attachedto the base plate, and a counterweight for biasing the pick-up shoe intophysical contact with the wayside conductor rail.

Yet other aspects of the present invention include the structures,processes and methods comprising the steps described herein, and alsoinclude the processes and modes of operation of the systems and devicesdescribed herein. Other aspects and embodiments of the present inventionwill become apparent from the detailed description of the invention whenread in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention described herein are exemplary, andnot restrictive. Embodiments will now be described, by way of examples,with reference to the accompanying drawings. In these drawings, eachidentical or nearly identical component that is illustrated in variousfigures is represented by a like reference character. For purposes ofclarity, not every component is labeled in every drawing. The drawingsare not necessarily drawn to scale, with emphasis instead being placedon illustrating various aspects of the techniques and devices describedherein.

FIG. 1A is an elevation view of a three-pocket railroad hopper carhaving a transverse door associated with each hopper, according to oneembodiment of the present invention.

FIG. 1B is a transverse view of the three-pocket hopper car shown inFIG. 1A.

FIG. 2A shows a perspective view of a body of a three-pocket railroadhopper car, according to one embodiment of the present invention.

FIG. 2B is a longitudinal section view of the hopper car body shown inFIG. 2A.

FIG. 3A is a perspective view of a transverse bottom discharge door in aclosed position, according to one embodiment of the present invention.

FIG. 3B is an elevation view of the transverse bottom discharge doorshown in FIG. 3A.

FIG. 4 is a top perspective view of a bottom discharge door in a closedposition, according to one embodiment of the invention.

FIG. 5A is a side perspective view of a bottom discharge door in aclosed position, according to one embodiment of the invention.

FIG. 5B is a side perspective view of a bottom discharge door in an openposition, according to one embodiment of the invention.

FIG. 6A is an elevation view of a bottom discharge door seal shown inFIG. 5A.

FIG. 6B is an elevation view of a first seal member of the bottomdischarge door seal shown in FIG. 6A.

FIG. 6C is an elevation view of a second seal member of the bottomdischarge door seal shown in FIG. 6A.

FIG. 7 is an elevation side view of a railroad hopper car door-actuatingassembly mounted in position on a railcar, according to one embodimentof the invention.

FIG. 8A is an elevation view of a railroad pick-up shoe, according toone embodiment of the invention.

FIG. 8B is a front view of the pick-up shoe shown in FIG. 8A.

FIG. 8C is a top view of the pick-up shoe shown in FIG. 8A.

FIG. 9 is an elevation view of the pick-up shoe shown in FIG. 8A,mounted on a railroad car sitting on a railroad track, according to oneembodiment of the invention.

FIG. 10 is an elevation view of the pick-up shoe shown in FIG. 8A,mounted on a railroad car traveling along a railroad track, according toone embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Overview

In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the invention. It will be apparent, however, to oneskilled in the art that the invention can be practiced without thesespecific details. In other instances, structures, devices, activities,and methods are shown using schematics, use cases, and/or flow diagramsin order to avoid obscuring the invention. Although the followingdescription contains many specifics for the purposes of illustration,anyone skilled in the art will appreciate that many variations and/oralterations to suggested details are within the scope of the presentinvention. Similarly, although many of the features of the presentinvention are described in terms of each other, or in conjunction witheach other, one skilled in the art will appreciate that many of thesefeatures can be provided independently of other features. Accordingly,this description of the invention is set forth without any loss ofgenerality to, and without imposing limitations upon, the invention.Furthermore, in the descriptions and in the claims which follow, the useof such words as “left”, “right”, “clockwise”, “counterclockwise”,“distal”, “proximal”, “forward”, “outward”, “rearward”, “vertical”,“horizontal”, and the like is in conjunction with the drawings forpurposes of clarity.

Broadly, embodiments of the present invention relate to railroad hoppercar design. More specifically, embodiments of the present invention aredirected to bottom discharge doors having angled seal lips that engageand interlock tightly and securely to prevent leakage of commoditymaterials. An angled door seal utilizes a unique structure to achievehigh and long-lasting sealing performances, while also reducing thedependence on elastic materials such as rubber, which often deteriorateunder use and over time.

Embodiments of the present invention are further directed to mechanismsand device assemblies for actuating bottom discharge doors whileeliminating sparking that may cause dust explosions in confined spaces.Conventionally, automatic bottom discharge hopper cars use pick-up shoesthat rub or slide against an electrified “hot” rail at dumping sites togenerate and transmit electrical signals to an electro-pneumatic controlvalve to open or close discharge doors. Any minor discontinuation in thephysical contact between a pick-up shoe and a hot rail may create aspark. Described herein are door-actuating assemblies that utilize arechargeable battery to eliminate the potential presence of sparks. Therechargeable battery is charged via the pick-up shoe prior to the hoppercar entering a loading site, when a hermetically sealed switch is turnedoff to insulate the battery from the control valve. The pick-up shoe isthen de-activated with a biasing mechanism. Inside the loading site, thehermetically sealed switch may be turned on to allow the battery todischarge and activate the control valve, enabling automatic dischargewithout sparking hazards. An additional benefit of the actuatingassembly as disclosed herein is that when the hermetically sealed switchis left on, the hopper car may function as a conventional, fullyautomatic, dump-in-motion car, thus enabling existing automatic bottomdischarge hopper cars to be upgraded without mandatory changes to dumpsite rail layouts.

With reference to the definitions above and the figures provided,embodiments of the present invention are now described in detail.

Discharge Door Seal

FIG. 1A is an elevation view 100 of a three-pocket railroad hopper car102 having transverse bottom discharge doors with angled seals,according to one embodiment of the present invention. Correspondingly,FIG. 1B shows a transverse view 150 of the three-pocket hopper car 102.Car 102 may be provided with a plurality of hopper units 104, aplurality of wheels 105 mounted on a series of truck axles 107, and alongitudinally extending center sill 106. Each hopper unit 104 may beprovided with a bottom discharge door device 109 which is moveable toopen and close each hopper unit 104. For example, one or more doorplates of door 109 may be rotatable between a closed position and anopen position. An actuating system for this type of bottom dischargehopper car may be mounted to car 102 on the underside of sill 106 toprovide power. The operation of air cylinders is well known in the art,and it is within the scope of the present invention to use any suitablepower source such as an electric one to operate such cylinders. Oneexemplary actuating system is taught in U.S. Pat. No. 7,080,599, issuedon Jul. 25, 2006, which is incorporated by reference in its entirelyherein.

To improve the sealing effect of bottom discharge door device 109,members of angled door seals 110 are attached to individual door platesrespectively. Although bottom discharge door device 109 is shown astransverse in FIG. 1, an angled door seal as disclosed herein may beutilized with longitudinal bottom discharge door devices as well,mounted on railcars, trailers, or any other vehicle with dischargecompartments, including tractors. In addition, Although the system asdisclosed below teaches the operation of a single door device having asingle pair of door plates, the actuating mechanism as disclosed hereinmay also be used to open multiple sets of transverse or longitudinaldoor devices.

FIG. 2A shows a perspective view 200 of a body of a three-pocketrailroad hopper car, according to one embodiment of the presentinvention. In this embodiment, angled doors seals 210 are shownexplicitly for illustration purposes only, not necessarily to scale. Inthis embodiment, air cylinder 220 is attached to an end of the car bodyinstead of to a bottom center sill.

FIG. 2B shows a longitudinal section view 250 of the hopper car bodyshown in FIG. 2A, with the near side beam removed to reveal internaldetails. In this embodiment, rather than having full-width hopperdischarge doors, there are two half-width discharge doors mounted oneither side of center sill 256, which itself is protected from abrasionor other damages by shrouds 258. Directly visible in FIG. 2B is bottomdischarge door 259, with angled seal 210. In different embodiments, eachpair of bottom discharge doors separated by the center sill may beactuated jointly using the same door-actuating assembly.

FIG. 3A is a perspective view 300 of a transverse bottom discharge doordevice with an angled seal 210, in a closed position, according to oneembodiment of the present invention. FIG. 3B is a corresponding crosssection view 350. In FIG. 3A, a side panel of the door is removed toshow internal details.

FIG. 4 is a top perspective view 400 of a bottom discharge door device460 in a closed position, according to one embodiment of the invention.Door 460 comprises two door plates 430 and 440, one or both of which maybe hinged at its outer edge, and rotatable between an open position anda close position. Thus, both door plates may be movable, or one may bestationary while the other one is movable. When door 460 is in theclosed position as shown in FIG. 4, door plates 430 and 440 cometogether at edge 450. Similar to doors shown in FIG. 3A, door plates 430and 440 are slanted when closed, and one or more side panels 422 may befixed in place to close off the door device. In some embodiments wheredoor 460 is full-width, components 410, 412, 414, and 416 may representthe four sidewalls of a hopper respectively. In some embodiments wheredoor 460 is only half-width, similar to that shown in FIGS. 2A to 3B,components 410, 412, 414, and 416 may represent sidewalls of a hopper aswell as a center sill-protecting shroud. For example, side component 422may correspond to shroud 258 shown in FIG. 2B.

FIG. 5A is a side perspective view 500 of the bottom discharge door 460in a closed position, according to one embodiment of the invention. FIG.5B is a side perspective view 550 of the bottom discharge door 460 in anopen position. An angled seal 510 is formed by interlocking seal members530 and 540 when door 460 is in the closed position. First seal member530 is fixedly connected or mounted to door plate 530 through attachmentportion 532, with seal lip 534 protruding from a distal edge of doorplate 430, shown as edge 450 in FIG. 5A. Similarly, a second seal member540 is fixedly connected or mounted to door plate 440 through attachmentportion 542, with seal lip 544 protruding from a distal edge of doorplate 440, shown as edge 450. Both seal members may be made of metals oralloys such as steel, and the fixed connections may be made by welding,bolting, clamping, or any other appropriate attachment means. In someembodiments, attachment portions 532 and 542 may be absent, where theseal lips 534 and 544 may be attached to the distal edge of the doorplates directly. In either case, seal 510 may be added to conventionalbottom discharge doors as upgrades to improve their general sealingperformances.

In this embodiment, a bent is made to seal lip 534 to form an obtuseangle 535 on the lower surface of seal lip 534, and another bent is madeto seal lip 544 to form another angle 545 slightly smaller than angle535, on the upper surface of seal lip 545. As shown in FIG. 5A, the twoangles interlock to form seal 510 when door 460 is in the closedposition. At the coming together of the door plates, engagements of seallips 534 and 544 may cause a flexing or elastic deflection of each seallip, as the “female” angle 545 is slightly smaller than the “male” angle535. A tight and secure seal 510 is therefore formed to prevent leakageof commodity materials from the hoppers.

Furthermore, in this embodiment, a downward bent may be made to form anangle 536 between attachment portion 532 and seal lip 534 on the left,while a similar bent may be made to form angle 546 between attachmentportion 542 and seal lip 544. These angles are formed to serve at leasttwo purposes. First, they conform to the degree to which door plates 430and 440 are slanted. Second, they ensure that the door plates may beclosed in any order, even though protruding, overlapping seal lips arepresent. In some embodiments, angle 536 may be between 140 and 150degrees. In some embodiments, angle 536 may be 180 degrees while 546 maybe made smaller in accommodation.

FIG. 6A is a zoomed-in elevation view 600 of the bottom discharge doorseal 510 shown in FIG. 5A. Correspondingly, FIGS. 6B and 6C shownrespective elevation views of each seal member 530 and 540 of the bottomdischarge door seal shown in FIG. 6A. More specifically, FIGS. 6B and 6Cshow exemplary dimensions and angles of each seal member, according toone embodiment of the present invention. For example, obtuse angle 535is shown as 93° in FIG. 6A, angle 536 is set to 148°, and both angles545 and 546 are right angles at 90°. In various embodiments, obtuseangle 535 may take on values within different intervals, for example,between 93 degrees inclusive and 95 degrees inclusive, between 90degrees and 93 degrees, between 90 degrees and 95 degrees, and between93 degrees and 100 degrees. Each interval may include or exclude one orboth boundary values. Similarly, angle 536 may be between 130 and 145degrees, 140 and 150 degrees, 150 and 165 degrees, or 165 and 180degrees. The lengths of each arm of angles 535, 536, 545, and 546 aremeasured in terms of inches in FIGS. 6B and 6C. In addition, the radiusof curvature for angles 535, 545, and 546 are set at 0.5 inch,respectively, in this embodiment of the invention. Having a non-zerocurvature may enable an easier manufacturing process. In otherembodiments of the present invention, the radius of curvature for eachangle shown may take on different values within the range between 0inclusive and 5 inches inclusive.

Pick-Up Shoe

Conventional bottom discharge hopper cars are typically operated via anelectro-pneumatic valve, where an electrical signal activates a controlvalve such as a directional solenoid valve, to allow pneumatic actuationof the doors. Generally, solenoid valve activation is initiated by theelectrical signal, but the actual movement of the valve elements isachieved using air pressure. The electrical control signal is collectedusing a pick-up shoe from a wayside conductor rail, and transmitted tothe control valve. In some systems, when a positive direct-currentvoltage such as 24 VDC is present on the conductor rail and the pick-upshoe, while a negative direct current voltage such as −24 VDC is presenton a corresponding ground connection such as a regular rail, a signalmay be sent through an “open” solenoid to actuate an air cylinder suchas 220 to open the bottom discharge doors. When the voltages arereversed, a signal may be sent through a “close” solenoid to close thedoors. When the pick-up shoe is in the active position, rubbing againstthe conductor rail, sparks may be created. Embodiments of the presentinvention improves on the conventional design to eliminate the sparkingissue by separating the electrical signal collection process and thedoor-actuating process.

FIG. 7 is an elevation side view 700 of a railroad hopper cardoor-actuating assembly 705 mounted in position on a railcar, accordingto one embodiment of the present invention. In this embodiment,door-actuating assembly 705 comprises a battery 780 electricallyconnected on one end to a pick-up shoe 710, and on the other end to ahermetically sealed switch 782. The hermitically seal switch 782 is inturn electrically connected to battery 780 at terminal 781, and to anelectro-pneumatic valve 784 at terminal 783. Resistors 785, 786, 787,and similar electronic components such as diodes and circuit breakers(not shown) may be inserted in between pick-up shoe 710, battery 780,hermetically sealed switch 782, and electro-pneumatic valve 784, basedon additional system and circuit design goals.

In some embodiments of the present invention, battery 780 may berechargeable via pick-up shoe 710 when pick-up shoe 710 is biased intoan active position having physical contact with an electrified waysideconductor rail. This recharging process may be performed outside a dumpsite, with the hermetically sealed switch 782 turned off and battery 780grounded separately to complete the circuit. In some embodiments,rechargeable battery 780 may be an industrial strength capacitor thatmay be charged and discharged quickly to provide the desired electricalcontrol signal. Exemplary capacitor designs include, but are not limitedto, ceramic capacitors, electrolytic capacitors, tantalum capacitors,silver mica capacitors, polystyrene film capacitors, polyester filmcapacitors, metalized polyester film capacitors, polycarbonatecapacitors, polypropylene capacitors, glass capacitors, and supercapcapacitors. In some embodiments, rechargeable battery 780 may compriseone or more electrochemical cells. In some embodiments, rechargeablebattery 780 may be of high durability, capable of being operated inextreme temperatures and wear conditions.

Once rechargeable battery 780 is charged beyond a pre-determined stateof charge to ensure a desired terminal voltage may be obtained once loadis applied, pick-up shoe 710 may be biased again into an inactiveposition not having physical contact with the way side conductor rail,eliminating further occurrence of sparks. The state of charge (SOC) of abattery expresses a present battery capacity as a percentage of amaximum capacity; the terminal voltage is the voltage between thebattery terminals with load applied, varying with SOC and dischargecurrent. For example, the conductor rail may be designed with a lengththat ensure when the railroad hopper car moves along the track, therechargeable battery may be charged to an SOC of 80%. One the railroadcar enters the dump site with the pick-up shoe inactivated, hermeticallysealed switch 782 may be turned on, automatically or manually, so thatrechargeable battery 780 may send an electrical signal toelectro-pneumatic valve 784 to open or close bottom discharge doors 790.By utilizing rechargeable battery 780 and hermetically sealed switch782, the door-actuating process may be separately conducted from theoperations of the pick-up shoe, thus eliminating the occurrence ofsparks within a dump site.

In different embodiments of the present invention, a pick-up shoe asdisclosed herein may be biased by a spring or a counter-weight. Inparticular, FIG. 7 shows a spring-less pick-up shoe 710 with acounterweight 772 attached through an arm 774. Pick-up shoe 710 isattached to an insulating bracket 712 which is rigidly affixed to arailroad car section 770 by a plurality of fasteners which extendthrough a plurality of openings 714.

FIGS. 8A to 8C show an elevation view 800, a front view 810, and a topview 820 of the railroad pick-up shoe 710. Bracket 712, which consistsof a first section 712 a and a second section 712 b perpendicular tosection 712 a, is coupled for rotation to a contact holder 716 by a pin718 which passes through a pair of openings 720 within holder 716. Pin718, which contains a head 722 and a through aperture 724, may be heldin place by a washer 726 and a cotter pin (not shown) or the likeinserted through aperture 724. Bracket 712 may be constructed from anon-conductive material such as plastic or another similar polymer toelectrically isolate pick-up shoe 710 from the body of the railcar.

An electrical contact 730 may be rotatably fastened within contactholder 716. Contact 730, which constitutes a tubular electrode, may bepositioned within holder 716 by a pin 732 such that contact 730 mayrotate within holder 716 around pin 732, which passes through openings734 within holder 716 and openings 736 within contact 730. Pin 732,which contains a head 738 and a through aperture 740, may be held inplace by a washer 742 and a cotter pin (not shown) or the like insertedthrough aperture 740. Contact 730 may be manufactured from a conductivematerial and acts as a commutator switch between the trackside rail andthe railcar itself.

FIG. 9 is an elevation view 900 of the pick-up shoe 710 shown in FIG.8A, mounted on a railroad car sitting on a railroad track, according toone embodiment of the invention. In FIG. 9, a railroad car section 770is shown in its operating position affixed to pick-up shoe 710 usingfasteners which pass through openings 714 of bracket 712. Alternatively,item 770 may be a separate bracket which attaches directly to therailroad car. A counterweight 772 is attached to contact holder 716 byan arm 774. Counterweight 772 acts to hold contact 730 in constantrolling contact with the trackside rail while the car is in motion whenit is desired to provide electrical power to the railroad car.Counterweight 772 may weight up to four pounds in some embodiments ofthe present invention.

More specifically, FIG. 9 shows the pick-up shoe 710 in three positions:the operating position (as shoe 710), the intermediate position (as shoe710′), and its inactive position (as shoe 710″). When shoe 710″ is inthe inactive position, it is held in place by a latch, which holds arm774. The pick-up shoe is fixed in the inactive position whenever it isnot in use providing operating power or electrical signal to therailroad car. The intermediate position is shifted away from the waysideor trackside rail where the pick-up shoe is inoperative or inactive. Inthe operating position, shoe 710 has been pivoted about pin 718 in acounterclockwise direction. Note that as counterweight 772 is attachedto the pick-up shoe, it tends to pull shoe 710′ toward the rail, thusshoe 710′ must be held in this position or it will move back intocontact with the rail.

FIG. 10 is an elevation view 1000 of the pick-up shoe 710 shown in FIGS.8A-8C, mounted on a railroad car traveling along a railroad track,according to one embodiment of the invention. Here pick-up shoe 710 isin operation, providing operating power to a door-actuating assembly(not shown). In FIG. 10, pick-up shoe 710 is affixed to a side panel1082 of a metal railroad car 1084 having a metal wheel 1086 whichtravels along one of a set of metal rails 1088 which are attached to aseries of railroad ties 1090. A trackside third rail or waysideconductor rail 1092 is mounted on a support 1094 along the edge of rails1088. A pair of conductors 1096 are connected to rail 1092 and also torail 1088. As the railroad car moves along rails 1088, contact 730 ofshoe 710 maintains rolling contact with rail 1092 which is electrifiedthrough conductor 1096. The current path is completed by virtue of carbody 1084 and wheel 1086, which constantly contacts rails 1088, andconductor 1096. Shoe 710 may be electrically isolated from car 1084 asbracket 712 may be composed of anon-conductive material. Thus,electrical current is available on the railroad car to operate a valvein the like which may be used to operate a discharge mechanism foropening and closing the doors of the hoppers.

As contact 730 is in constant rolling contact with rail 1092 duringoperation, wear on the contact is greatly reduced as compared to anelectrical contact in sliding contact with the rail, greatly increasingthe operating life of the pick-up shoe. In addition, the use ofcounterweight 772 to ensure proper consistent contact for shoe 710 withrail 1092 provides a reliable way to provide power to the railroad carincluding the door actuating mechanisms without the use of openings,which will fatigue after a limited number of usages.

One of ordinary skill in the art knows that the use cases, structures,schematics, and flow diagrams may be performed in other orders orcombinations, but the inventive concept of the present invention remainswithout departing from the broader scope of the invention. Everyembodiment may be unique, and methods/steps may be either shortened orlengthened, overlapped with the other activities, postponed, delayed,and continued after a time gap, such that every user is accommodated topractice the methods of the present invention.

Although the present invention has been described with reference tospecific exemplary embodiments, it will be evident that the variousmodification and changes can be made to these embodiments withoutdeparting from the broader scope of the invention. Accordingly, thespecification and drawings are to be regarded in an illustrative senserather than in a restrictive sense. It will also be apparent to theskilled artisan that the embodiments described above are specificexamples of a single broader invention which may have greater scope thanany of the singular descriptions taught. There may be many alterationsmade in the descriptions without departing from the scope of the presentinvention.

What is claimed is:
 1. A bottom discharge door, comprising: a first doorplate comprising a first hinged end and a first distal end opposite tothe first hinged end; a first seal member comprising a first attachmentportion and a first seal lip, wherein the first seal member is fixedlyconnected to the first distal end at the first attachment portion,wherein the first seal lip protrudes from the first distal end, andwherein the first seal lip comprises a first obtuse angle on a lowersurface of the first seal lip; a second door plate comprising a secondhinged end and a second distal end opposite to the second hinged end;and a second seal member comprising a second attachment portion and asecond seal lip, wherein the second seal member is fixedly connected tothe second distal end at the attachment portion, wherein the second seallip protrudes from the second distal end, wherein the second seal lipcomprises a second angle smaller than the first angle, on an uppersurface of the second seal lip, wherein at least one of the first andsecond door plates is rotatable around its hinged end, between a closedposition and an open position for the bottom discharge door, and whereinwhen the bottom discharge door is in the closed position, the firstobtuse angle interlocks with the second angle to form a seal.
 2. Thebottom discharge door of claim 1, wherein the first obtuse angle ismeasured between 93 degrees inclusive and 95 degrees inclusive.
 3. Thebottom discharge door of claim 1, wherein the second angle is a rightangle.
 4. The bottom discharge door of claim 1, wherein the firstattachment portion is a flat plate, wherein the first attachment portionand the first seal lip form a third angle on a lower surface of thefirst seal member, and wherein the third angle is measured between 145degrees inclusive and 150 degrees inclusive.
 5. The bottom dischargedoor of claim 1, wherein the second attachment portion is a flat plate,and wherein the second attachment portion and the second seal lip form aright angle on a lower surface of the second seal member.
 6. The bottomdischarge door of claim 1, wherein the first seal member is fixedlyconnected the first distal end at the first attachment portion throughwelding, bolting, or clamping, and wherein the second seal member isfixedly connected to the second distal end at the second attachmentportion through welding, bolting, or clamping.
 7. The bottom dischargedoor of claim 1, wherein each of the first and second seal lipselastically deflects when the bottom discharge door is in the closedposition.
 8. The bottom discharge door of claim 1, wherein each arm ofeach of the first obtuse angle and the second angle measures at least 2inches in length.
 9. A railroad hopper car with bottom discharge doorshaving angled seals, comprising: a body; a plurality of hoppers along anunderside of the body; and a plurality of bottom discharge doorssituated on the underside of body for opening and closing the pluralityof hoppers, each bottom discharge door comprising: a first door platecomprising a first hinged end and a first distal end opposite to thefirst hinged end; a first seal member comprising a first attachmentportion and a first seal lip, wherein the first seal member is fixedlyconnected to the first distal end at the first attachment portion,wherein the first seal lip protrudes from the first distal end, andwherein the first seal lip comprises a first bent forming a first obtuseangle on a lower surface of the first seal lip; a second door platecomprising a second hinged end and a second distal end opposite to thesecond hinged end; and a second seal member comprising a secondattachment portion and a second seal lip, wherein the second seal memberis fixedly connected to the second distal end at the attachment portion,wherein the second seal lip protrudes from the second distal end,wherein the second seal lip comprises a second bent forming a secondangle smaller than the first obtuse angle, on an upper surface of thesecond seal lip, wherein at least one of the first and second doorplates is rotatable around its hinged end, between a closed position andan open position for the bottom discharge door, and wherein when thebottom discharge door is in the closed position, the first obtuse angleinterlocks with the second angle to form a seal between the first sealmember and the second seal member.
 10. The railroad hopper car of claim9, wherein the first obtuse angle is measured between 93 degreesinclusive and 95 degrees inclusive.
 11. The railroad hopper car of claim9, further comprising a door-actuating assembly for actuating the bottomdischarge doors, wherein the door-actuating assembly comprises: apick-up shoe; a battery electrically connected to the pick-up shoe,wherein the battery is rechargeable via the pick-up shoe when thepick-up shoe is biased into an active position having physical contactwith a wayside conductor rail; a hermetically sealed switch electricallyconnected to the battery at a first terminal; and an electro-pneumaticvalve electrically connected to the hermetically sealed switch at asecond terminal, for actuating at least one bottom discharge doorbetween the open position and the closed position, after the battery ischarged beyond a pre-determined state of charge, and after the pick-upshoe is biased into an inactive position not having physical contactwith the wayside conductor rail.
 12. The railroad hopper car of claim11, wherein the battery is a capacitor.
 13. The railroad hopper car ofclaim 11, wherein the electro-pneumatic valve operates between 24 VDCand −24 VDC.
 14. The railroad hopper car of claim 11, wherein thepick-up shoe is spring-biased.
 15. The railroad hopper car of claim 11,wherein the pick-up shoe further comprises: a base plate adapted to beattached to the railroad hopper car; an electrical contact attached tothe base plate; and a counterweight for biasing the pick-up shoe intophysical contact with the wayside conductor rail.
 16. The railroadhopper car of claim 9, wherein the second angle is a right angle. 17.The railroad hopper car of claim 9, wherein the first attachment portionis a flat plate, wherein the first attachment portion and the first seallip form a third angle on a lower surface of the first seal member, andwherein the third angle is measured between 145 degrees inclusive and150 degrees inclusive.
 18. The railroad hopper car of claim 9, whereinthe second attachment portion is a flat plate, and wherein the secondattachment portion and the second seal lip form a right angle on a lowersurface of the second seal member.
 19. The railroad hopper car of claim9, wherein the first seal member is fixedly connected the first distalend at the first attachment portion through welding, bolting, orclamping, and wherein the second seal member is fixedly connected to thesecond distal end at the second attachment portion through welding,bolting, or clamping.
 20. The railroad hopper car of claim 9, whereineach of the first and second seal lips elastically deflects when thebottom discharge door is in the closed position.